Referencing Cluster volumes

[cherbst]

Description

If I am correct it is currently not possible to use cluster volumes in a docker-compose.yml file like with docker commands:
https://github.com/moby/moby/blob/master/docs/cluster_volumes.md
On the service level the volume directive only supports pipe,npipe,tmpfs and volume . Probably a cluster type should be added or the top level volumedirective needs a type parameter.

[ndeloof]

According to this doc, such a volume can be created by docker volume create with adequate driver options, and listed by docker volume ls. So you should be able to do the same with a top-level volume (not by service) entry to use the required driver and driver-opts, or refer to an external volume by name if you want to use an existing one.